Low profile plate

ABSTRACT

The present application generally relates to orthopedic systems, and in particular, to systems including independent plates and spacers. A plating system can include a spacer and a plate that is independent from the spacer. A number of locking mechanisms can be provided to secure the plate to the spacer. In some cases, the spacer includes a pair of notches that extend on an outer surface of the spacer. The plate can include a pair of lateral extensions that can engage the notches to secure the plate to the spacer. In other cases, the spacer includes an opening including a pair of inlets. The plate can include an enclosed posterior extension that can be received in the pair of inlets to secure the plate to the spacer.

CROSS REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation of U.S. patent applicationSer. No. 13/785,434 filed on Mar. 5, 2013, which is incorporated in itsentirety herein.

FIELD OF THE INVENTION

The present application is generally directed to orthopedic systems, andin particular, to systems including plates and spacers.

BACKGROUND

Spinal discs and/or vertebral bodies of a spine can be displaced ordamaged due to trauma, disease, degenerative defects, or wear over anextended period of time. One result of this displacement or damage maybe chronic back pain. In some cases, to alleviate back pain, the disccan be removed and replaced with an implant, such as a spacer, thatpromotes fusion. In addition to providing one or more spacers, a platingsystem can be used to further stabilize the spine during the fusionprocess. Such a plating system can include one or more plates and screwsfor aligning and holding vertebrae in a fixed position with respect toone another.

Accordingly, there is a need for improved systems involving platingsystems and spacers for spinal fusion and stabilization.

SUMMARY OF THE INVENTION

Various systems, devices and methods related to plating systems areprovided. In some embodiments, a spinal system comprises a spacer forinserting into an intervertebral space and a plate configured to abutthe spacer. The spacer can include an upper surface, a lower surface andan opening that extends between the upper surface to the lower surface,wherein the spacer further includes a tapered leading end. The plate forabutting the spacer can include a plate body, a first opening formed inthe plate body for receiving a first bone screw, a second opening formedin the plate body for receiving a second bone screw, a set screw, and apair of extensions that extend from the plate body that are configuredto engage the spacer. The first opening can angled in an upwarddirection, while the second opening can be angled in a downwarddirection. The set screw can be configured to prevent back-out of boththe first and the second bone screws, wherein the set screw has a firstposition whereby the first and second bone screws can be inserted pastthe set screw and into the first and second openings and a secondposition following rotation of the set screw whereby the first andsecond bone screws are prevented from backing out by the set screw. Afirst bone screw is provided for inserting into the first opening in theplate body, wherein the first bone screw is configured to be insertedinto a first vertebral body. A second bone screw is provided forinserting into the second opening in the plate body, wherein the secondbone screw is configured to be inserted into a second vertebral bodydifferent from the vertebral body.

In other embodiments, a spinal system comprises a spacer for insertinginto an intervertebral space and a plate configured to abut the spacer.The spacer can include an upper surface, a lower surface and an openingthat extends between the upper surface to the lower surface, wherein thespacer further includes a concave leading end. The plate for abuttingthe spacer can include a plate body, a first opening formed in the platebody for receiving a first bone screw, a second opening formed in theplate body for receiving a second bone screw, a set screw, and a pair ofextensions that extend from the plate body that are configured to engagethe spacer. The first opening can angled in an upward direction, whilethe second opening can be angled in a downward direction. The set screwcan be configured to prevent back-out of at least one of the first andthe second bone screws, wherein the set screw has a first positionwhereby at least one of the first and second bone screws can be insertedpast the set screw and into at least one of the first and secondopenings and a second position following rotation of the set screwwhereby at least one of the first and second bone screws are preventedfrom backing out by the set screw. Each of the pair of extensions caninclude a window that extends along a length of the extension. A firstbone screw is provided for inserting into the first opening in the platebody, wherein the first bone screw is configured to be inserted into afirst vertebral body. A second bone screw is provided for inserting intothe second opening in the plate body, wherein the second bone screw isconfigured to be inserted into a second vertebral body different fromthe vertebral body.

In some embodiments, a spinal system comprises a spacer for insertinginto an intervertebral space and a plate configured to abut the spacer.The spacer can include an upper surface, a lower surface and an openingthat extends between the upper surface to the lower surface. The platefor abutting the spacer can include a plate body, a first opening formedin the plate body for receiving a first bone screw, a second openingformed in the plate body for receiving a second bone screw, a set screw,and a pair of extensions that extend from the plate body that areconfigured to engage the spacer. The first opening can angled in anupward direction, while the second opening can be angled in a downwarddirection. The set screw can be configured to prevent back-out of atleast one of the first and the second bone screws, wherein the set screwhas a first position whereby at least one of the first and second bonescrews can be inserted past the set screw and into at least one of thefirst and second openings and a second position following rotation ofthe set screw whereby at least one of the first and second bone screwsare prevented from backing out by the set screw. Each of the pair ofextensions can include a window that extends along a length of theextension. A first bone screw is provided for inserting into the firstopening in the plate body, wherein the first bone screw is configured tobe inserted into a first vertebral body. A second bone screw is providedfor inserting into the second opening in the plate body, wherein thesecond bone screw is configured to be inserted into a second vertebralbody different from the vertebral body. The spacer and the plate areindependent from one another such that the spacer can be inserted into adesired spinal location prior to abutting the spacer with the plate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1D illustrate different views of a low profile plate attachedto a spacer according to some embodiments.

FIGS. 2A-2D illustrate different views of the low profile plate shown inFIGS. 1A-1D.

FIGS. 3A-3D illustrate different views of a PEEK spacer to be used withthe low profile plate shown in FIGS. 2A-2D.

FIGS. 4A-4D illustrate different views of an allograft spacer to be usedwith the low profile plate shown in FIGS. 2A-2D.

FIGS. 5A-5D illustrate different views of a second alternativeembodiment of a low profile plate attached to a spacer according to someembodiments.

FIGS. 6A-6D illustrate different views of the low profile plate shown inFIGS. 5A-5D.

FIGS. 7A-7D illustrate different views of a PEEK spacer to be used withthe low profile plate in FIGS. 6A-6D.

FIGS. 8A-8D illustrate different views of an allograft spacer to be usedwith the low profile plate in FIGS. 6A-6D.

FIGS. 9A-9D illustrate different views of a third alternative embodimentof a low profile plate attached to a spacer according to someembodiments.

FIGS. 10A-10D illustrate different views of the low profile plate shownin FIGS. 9A-9D.

FIGS. 11A-11D illustrate different views of a fourth alternativeembodiment of a low profile plate attached to a spacer according to someembodiments.

FIGS. 12A-12D illustrate different views of the low profile plate shownin FIGS. 11A-11D.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

The present application is generally directed to orthopedic systems, andin particular, to systems including plates and spacers.

The present application discloses orthopedic plating systems that can beused in spinal surgeries, such as spinal fusions. The plating systemsdisclosed herein include a plate and a spacer that are independent fromone another. In some cases, the plate and the spacer can be pre-attachedto one another before positioning them in a desired location of thespine. In other cases, the spacer can first be inserted into a desiredlocation of the spine, and then the plate can be inserted thereafter.Advantageously, the plating systems disclosed herein are of low-profile.For example, they can provide a very small, anterior footprint cervicalplate solution for fusion procedures. One skilled in the art willappreciate that while the plating systems can be used with cervicalprocedures, the plating systems are not limited to such areas, and canbe used with other regions of the spine.

FIGS. 1A-1D illustrate different views of a plating system comprising alow profile plate attached to a spacer according to some embodiments.The plating system 5 includes a spacer 10 attached to a low-profileplate 50. Advantageously, the plating system 5 can be inserted throughan anterior approach into a spine, and can desirably provide a smallanterior footprint.

The spacer 10 is configured to have an upper surface 12, a lower surface14, and a leading end 22. In some embodiments, the upper surface 12and/or lower surface 14 includes texturing 16, such as teeth, ribs,ripples, etc. to assist in providing frictional contact with adjacentvertebral bodies. In some embodiments, the leading end 22 of the spacer10 can be slightly tapered, as shown in FIG. 1A. With the taper, theleading end 22 can serve as a distraction surface that helps the spacerto be inserted into an intervertebral space. As shown in FIG. 1B, theleading end 22 can be concave, though in other embodiments, the leadingend 22 can be straight or convex.

The spacer 10 can be substantially C-shaped (as shown in FIG. 3B),whereby it includes two side arms 13 that surround an inner opening 20.Adjacent the side arms 13 is a convex wall 19. In some embodiments, theconvex wall 19 is substantially parallel to the concave surface of theleading end 22. The opening 20, which is configured to receive naturalor synthetic graft material therein to assist in a fusion procedure, hasan open side that is opposite convex wall 19, thereby giving the spacer10 its C-shape.

The spacer 10 has a number of unique features that accommodate theattachment of a plate 50 thereto. Each of the side arms 13 of the spacer10 includes a notch 17 (shown in FIG. 3B) for receiving a correspondingprotrusion 71 of a lateral arm or extension 70 of the plate 50, therebyadvantageously forming a first locking mechanism between the spacer 10and the plate 50. In addition, in some embodiments, each of the sidearms 13 of the spacer 10 can also include a hump region 26 (shown inFIG. 3B) that can extend in part into a window 72 of an attached plate50 (shown in FIG. 2A), thereby advantageously providing a second lockingmechanism between the spacer 10 and the plate 50. Advantageously, byproviding secure first and second locking mechanisms between the spacer10 and the plate 50, the plate and spacer will be kept securely togetherduring any type of impaction of the plating system within the body.Furthermore, each of the side arms 13 of the spacer 10 can include acut-away portion or chamfer 18, 19 (shown in FIG. 3C) to advantageouslyaccommodate screws which pass through the plate. In embodiments thatinvolve a pair of screws through the plate 50—one of which passes in anupward direction, and the other of which passes in a downwarddirection—one side arm 13 of the spacer 10 will include an upper chamfer18 formed on an upper surface to accommodate the upwardly directedscrew, while the second side arm 13 of the spacer will include a lowerchamfer 19 formed on a lower surface to accommodate the downwardlydirected screw.

The spacer 10 can be formed of any material. In some embodiments, thespacer 10 is formed of a polymer, such as PEEK, as shown in FIG. 3A. Insome embodiments, the spacer 10 is formed of allograft bone, as shown inFIG. 4A. In some instances, to form an allograft implant, allograft bonemay be cut or shaved from a desired bone member. The cut allograft bonewill then be assembled together, using an adhesive or mechanicalfastener (e.g., bone pins). Accordingly, in some embodiments, anallograft spacer 10 is formed of two, three, four or more layers thatare assembled together, such as by one or more bone pins. One particularadvantage of the invention is that the plate 50 can work with a varietyof different spacers 10, as the plate 50 is independently removable fromand attachable to the spacer 10. Regardless of whether a surgeon choosesto implant an allograft spacer or PEEK spacer 10 into an intervertebralspace, the surgeon can simply attach the low-profile plate 50 to thespacer 10 following implantation into the intervertebral space.

The plate 50 is configured to have a plate body and a pair of lateralextensions 70 that extend from the plate body, each of which has aprotrusion 71, for inserting into a corresponding notch 17 of the spacer10. These lateral extensions 70 help form the first locking mechanismbetween the plate 50 and the spacer 10, as discussed above. In addition,the lateral extensions 70 of the plate 50 each include a window 72(shown in FIG. 2A) for receiving a hump region 26 on the arms 17 of thespacer 10, thereby helping to form the second locking mechanism betweenthe plate 50 and the spacer 10, as discussed above.

In addition to attaching to the spacer 10, the plate 50 is alsoconfigured to attach into one or more vertebral bodies via one or morebone screws. As shown in FIG. 1A, the plate 50 includes a first screwhole 52 and a second screw hole 54 for receiving bone screws therein. Insome embodiments, screw hole 52 is angled upwardly such that an insertedbone screw passes upward into an upper vertebral body, while screw hole54 is angled downwardly such that an inserted bone screw passes downwardinto a lower vertebral body. While the illustrated embodimentillustrates a pair of screw holes for receiving a pair of bone screws,it is possible to have one, three, four, five or more screw holes forreceiving a different number of bone screws.

Over time, it is possible for bone screws to back-out. The plate 50 thushas a blocking or set screw 56 (shown in FIG. 1C) that assists inpreventing back-out of inserted bone screws. As shown in FIG. 1C, theset screw 56 can be in an initial position that allows first and secondbone screws to pass through holes 52, 54. Once the bone screws have beeninserted through the holes 52, 54, the set screw 56 can be rotated(e.g., 90 degrees), to thereby block the bone screws and prevent backout of the bone screws. In some embodiments, the set screw 56 abuts aside of the head of the bone screws to prevent back-out of the bonescrews, while in other embodiments, the set screw 56 rests over a top ofthe head of the bone screws to prevent back-out of the bone screws. Insome embodiments, the set screw 56 comes pre-fixed with the plate 50. Asshown in FIG. 1C, a single set screw 56 can be used to convenientlyblock a pair of bone screws. In other embodiments, each bone screw canbe assigned its own set screw, which can operate independently of oneanother, to prevent back-out of the bone screw.

The plate 50 can also include one or more knife-like edges 63 thatprovide additional torsional stabilization when the plate 50 restsagainst a bone member. As shown in FIG. 1C, the knife-like edges 63 canbe formed on both the upper and lower surfaces of the plate 50 body.While the illustrated embodiment shows a pair of knife-like edges 63 onan upper surface of the plate body and a pair of knife-like edges 63 ona lower surface of the plate body, one skilled in the art willappreciate that a different number of knife-like edges 63 can beprovided.

FIGS. 2A-2D illustrate different views of the low profile plate shown inFIGS. 1A-1D. From these views, one can see the pair of lateralextensions 70 that extend from the body of the plate 50. At the distalend of each of the lateral extensions 70 is an inwardly-facingprotrusion 71 that is configured to fit into a corresponding notch inthe spacer 10. In addition, from these views, one can see the windows 72that are formed in each of the lateral extensions 70. The windows 72advantageously receive hump regions 26 of the spacer to provide alocking mechanism, and also help to improve desirable radiolucency.Advantageously, the windows 72 can have rounded edges to accommodate thespacer 10 therein. While the illustrated windows 72 are shown asrectangular with rounded edges, in other embodiments, the windows 72 canhave a different shape, such as circular or oval. In some embodiments,the plate 50 is assembled axially to the spacer 10.

In some embodiments, the low profile plate 50 can also include indentedgripping sections 73 (shown in FIGS. 2A and 2B). These indented grippingsections 73 advantageously provide a gripping surface for an insertioninstrument, thereby facilitating easy delivery of the plate to a spacerbody during surgery.

FIGS. 3A-3D illustrate different views of a PEEK spacer to be used withthe low profile plate shown in FIGS. 2A-2D. From these views, one cansee how the spacer 10 a includes an upper surface 12 a and a lowersurface 14 a with texturing 16 a; a generally C-shaped body including apair of arms 13 a each having a notch 17 a formed therein and an upperchamfer 18 a or lower chamfer 19 a; and a tapered leading edge 22 a. Inaddition, one skilled in the art can appreciate the substantiallysymmetric shape of the inner opening 20 a, which serves as a graft holefor receiving graft material therein.

FIGS. 4A-4D illustrate different views of an allograft spacer to be usedwith the lower profile plate shown in FIGS. 2A-2D. While the allograftspacer 10 b shares similar features to the PEEK spacer 10 a shown inprevious figures, such as the notches 17 b, hump surfaces 26 b, andchamfers 18 b,19 b, the allograft spacer 10 b need not be the same. Forexample, the shape of the graft opening 20 b can be more of an arch, asshown in FIG. 4B.

FIGS. 5A-5D illustrate different views of a second alternativeembodiment of a low profile plate attached to a spacer according to someembodiments. Rather than having a plate 50 with lateral extensions 70that extend around the outer surface of a spacer 10, the presentembodiment of the plating system 105 includes a plate 150 with anenclosed posterior extension 155 that fits within the body of the spacer110. The enclosed posterior extension 155 includes extending surfaces166, 167 that are fitted into corresponding inlets 121, 123 formed inthe body of the spacer 120, thereby forming a first locking mechanismbetween the plate 150 and the spacer 110. In addition, the enclosedposterior extension 155 of the plate 50 includes one or more deformablelocking tabs 160 (shown in FIG. 6B) that securely lock into tab holes181 a in the spacer body 110, thereby forming a second locking mechanismbetween the plate 150 and the spacer 110. While in some embodiments, theplate 150 can be attached to the spacer 110 after inserting the spacer110 into a desired location in the body, in other embodiments, the plate150 can be pre-assembled with the spacer 110 prior to inserting theplating system 105 into the desired location.

Like the spacer 10 in FIG. 1A, the spacer 110 is configured to have anupper surface 112, a lower surface 114, and a leading end 122. In someembodiments, the upper surface 112 and/or lower surface 114 includestexturing 116, such as teeth, ribs, ripples, etc. to assist in providingfrictional contact with adjacent vertebral bodies. In some embodiments,the leading end 122 of the spacer 110 can be slightly tapered, as shownin FIG. 7D. With the taper, the leading end 122 can serve as adistraction surface that helps the spacer 110 to be inserted into anintervertebral space. As shown in FIG. 1B, the leading end 122 can beconcave, though in other embodiments, the leading end 122 can bestraight or convex.

The spacer 110 can be substantially C-shaped (as shown in FIG. 7B),whereby it includes two side arms 113 that surround an inner opening120. Adjacent the side arms 113 is a straight wall 119 that forms theborder of the graft opening 120. The straight wall 119 can include oneor more tab holes 181 (shown in FIG. 7A) for receiving deformable tablocks 160 therein. The graft opening 20, which is configured to receivenatural or synthetic graft material therein to assist in a fusionprocedure, has an open side that is opposite the straight wall 119,thereby giving the spacer 110 its C-shape.

In some embodiments, the graft opening 120 (shown in FIG. 7B) has adifferent shape from the opening 20 of the spacer 10 of the priorembodiment, as the graft opening 120 is configured to not only receivegraft material, but also the enclosed posterior extension 155 of theplate 150. For example, the graft opening 120 includes two inlets—afirst inlet 121 formed at the junction between the first arm 113 andwall 119 and a second inlet 123 formed at the junction between thesecond arm 113 and wall 119 (shown in FIG. 7B)—for receiving outwardlyextending surfaces 166, 167 of the plate 150 (shown in FIG. 6B). Inaddition, the graft opening 120 includes two outwardly tapering walls111 that provide enough space to accommodate any bone screws inserted inthe plate 150. As such, additional chamfers 18, 19 (as shown in FIG. 3B)are optional.

Like spacer 10, the spacer 110 can be formed of a variety of materials.In some embodiments, the spacer 110 comprises PEEK, as shown in FIG. 7A,while in other embodiments, the spacer 110 comprises allograft bone, asshown in FIG. 8A.

The plate 150 is configured to have a plate body, and an enclosedposterior extension 155 that extends from the plate body, which isreceived within and retains the spacer 110. The enclosed posteriorextension 155 includes first and second outwardly extending surfaces166, 167 that fit into inlets 121, 123 formed within the spacer 110 bodyto form a first locking mechanism. In addition, one or more deformabletab locks 160 extend from an exterior surface of the enclosed posteriorextension 155 and are received in corresponding tab holes 181 in thespacer 150 to form a second locking mechanism. In some embodiments, theside walls of the enclosed posterior extension 155 can include one ormore windows 172 (shown in FIG. 6A) for improving radiolucency of theplating system. In some embodiments, the plate 150 is assembled axiallyto the spacer 110.

In addition to attaching to the spacer 110, the plate 150 is alsoconfigured to attach into one or more vertebral bodies via one or morebone screws 88, 89. As shown in FIG. 5A, the plate 150 includes a firstscrew hole 152 and a second screw hole 154 for receiving bone screws 88,89 therein. In some embodiments, screw hole 152 is angled upwardly suchthat an inserted bone screw 88 passes upward into an upper vertebralbody, while screw hole 154 is angled downwardly such that an insertedbone screw 89 passes downward into a lower vertebral body. While theillustrated embodiment illustrates a pair of screw holes for receiving apair of bone screws, it is possible to have one, three, four, five ormore screw holes for receiving a different number of bone screws.

Over time, it is possible for bone screws to back-out. The plate 150thus has a blocking or set screw 156 (shown in FIG. 5C) that assists inpreventing back-out of inserted bone screws. As shown in FIG. 5C, theset screw 156 can be in an initial position that allows first and secondbone screws to pass through holes 152, 154. Once the bone screws havebeen inserted through the holes 152, 154, the set screw 156 can berotated (e.g., 90 degrees), to thereby block the bone screws and preventback out of the bone screws. In some embodiments, the set screw 156abuts a side of the head of the bone screws to prevent back-out of thebone screws, while in other embodiments, the set screw 156 rests over atop of the head of the bone screws to prevent back-out of the bonescrews. In some embodiments, the set screw 156 comes pre-fixed with theplate 150. As shown in FIG. 5C, a single set screw 156 can be used toconveniently block a pair of bone screws. In other embodiments, eachbone screw can be assigned its own set screw, which can operateindependently of one another, to prevent back-out of the bone screw.

The plate 150 can also include one or more knife-like edges 163 thatprovide additional torsional stabilization when the plate 150 restsagainst a bone member. As shown in FIG. 5C, the knife-like edges 163 canbe formed on both the upper and lower surfaces of the plate 150 body.While the illustrated embodiment shows a pair of knife-like edges 163 onan upper surface of the plate body and a pair of knife-like edges 163 ona lower surface of the plate body, one skilled in the art willappreciate that a different number of knife-like edges 163 can beprovided.

FIGS. 6A-6D illustrate different views of the low profile plate shown inFIGS. 5A-5D. From these views, one can see the enclosed posteriorextension 155 that extends from the body of the plate 150. At the distalend of the enclosed posterior extension 155 are a pair of outwardlyextending surfaces 166, 167 that are configured to fit within inlets121, 123 formed in the spacer. From these views, one can also see thedeformable tab lock 160 (FIG. 6B) that can help secure the plate 150 tothe spacer 110. In addition, from these views, one can see the windows172 that are formed in each of the arms of the enclosed posteriorextension 155. The windows 172 advantageously help to improve desirableradiolucency, and are of large size to provide a large viewing surfacearea. While the illustrated windows 172 are shown as triangular withrounded edges, in other embodiments, the windows 172 can have adifferent shape, such as circular or oval. In some embodiments, theplate 150 is assembled axially to the spacer 110.

In some embodiments, the low profile plate 150 can also include indentedgripping sections 173 (shown in FIGS. 6A and 6B). These indentedgripping sections 173 advantageously provide a gripping surface for aninsertion instrument, thereby facilitating easy delivery of the plate toa spacer body during surgery.

FIGS. 7A-7D illustrate different views of a PEEK spacer to be used withthe low profile plate shown in FIGS. 5A-5D. From these views, one cansee how the spacer 110 a includes an upper surface 112 a and a lowersurface 114 a with texturing 116 a; a generally C-shaped body includinga pair of arms 113 a each having an inner inlet 121, 123 a formedtherein; and a tapered leading edge 122 a. In addition, one skilled inthe art can appreciate the substantially symmetric shape of the inneropening 120 a, which serves as a graft hole for receiving graft materialtherein.

FIGS. 8A-8D illustrate different views of an allograft spacer to be usedwith the lower profile plate shown in FIGS. 5A-5D. While the allograftspacer 110 b shares similar features to the PEEK spacer 110 a shown inprevious figures, such as the C-shaped body including a pair of arms 113b each having an inlet 121 b, 123 b formed therein, the allograft spacer110 b need not be the same.

FIGS. 9A-9D illustrate different views of a third alternative embodimentof a low profile plate attached to a spacer according to someembodiments. In the present embodiment, the plating system 205 includesa plate 250 having lateral arms or extensions 270 that extend around anexterior surface of a spacer 210. The lateral extensions 270 extendwider than the lateral extensions 70 in the first embodiment, and do notnecessarily have to interlock with the spacer 210. While in someembodiments, the plate 250 can be attached to the spacer 210 afterinserting the spacer 210 into a desired location in the body, in otherembodiments, the plate 250 can be pre-assembled with the spacer 210prior to inserting the plating system 205 into the desired location.

Like the spacer 10 in FIG. 1A, the spacer 210 is configured to have anupper surface 212, a lower surface 214, and a leading end 222. In someembodiments, the upper surface 212 and/or lower surface 214 includestexturing 216, such as teeth, ribs, ripples, etc. to assist in providingfrictional contact with adjacent vertebral bodies. In some embodiments,the leading end 222 of the spacer 210 can be slightly tapered, as shownin FIG. 9D. With the taper, the leading end 222 can serve as adistraction surface that helps the spacer 210 to be inserted into anintervertebral space. As shown in FIG. 9B, the leading end 222 can beslightly concave, though in other embodiments, the leading end 122 canbe straight or convex. Unlike previously illustrated spacers, the spacer210 can have a graft hole 220 that is completely enclosed. As shown inFIG. 9B, the graft hole 220 can surrounded by four walls. In addition,the spacer 210 can include four outer walls: two straight walls, aconvex wall and a concave wall.

In some embodiments, the graft opening 220 (shown in FIG. 9B) has adifferent shape from the openings of prior embodiments, as the graftopening 220 is enclosed. While the graft opening 220 is rectangular withrounded edges, in other embodiments, the graft opening 220 can have adifferent shape. For example, in some embodiments, the graft opening 220can have curved walls, instead of straight walls, or can have taperedwalls, instead of straight walls.

Like spacer 10, the spacer 210 can be formed of a variety of materials.In some embodiments, the spacer 210 comprises allograft bone, while inother embodiments, the spacer 210 comprises PEEK.

The plate 250 is configured to have a pair of lateral extensions 270that receive the spacer 220. As shown in FIG. 9A, in some embodiments,the lateral extensions 270 include one or more windows 272 for improvingradiolucency of the plating system. In some embodiments, the plate 250is assembled axially to the spacer 210.

In addition to capturing the spacer 210, the plate 250 is alsoconfigured to attach into one or more vertebral bodies via one or morebone screws 88, 89. As shown in FIG. 9A, the plate 250 includes a firstscrew hole 252 and a second screw hole 254 for receiving bone screws 88,89 therein. In some embodiments, screw hole 252 is angled upwardly suchthat an inserted bone screw 88 passes upward into an upper vertebralbody, while screw hole 254 is angled downwardly such that an insertedbone screw 89 passes downward into a lower vertebral body. While theillustrated embodiment illustrates a pair of screw holes for receiving apair of bone screws, it is possible to have one, three, four, five ormore screw holes for receiving a different number of bone screws.

Over time, it is possible for bone screws to back-out. The plate 250thus has a blocking or set screw 256 (shown in FIG. 9C) that assists inpreventing back-out of inserted bone screws. As shown in FIG. 9C, theset screw 256 can be in an initial position that allows first and secondbone screws to pass through holes 252, 254. Once the bone screws havebeen inserted through the holes 252, 254, the set screw 256 can berotated (e.g., 90 degrees), to thereby block the bone screws and preventback out of the bone screws. In some embodiments, the set screw 256abuts a side of the head of the bone screws to prevent back-out of thebone screws, while in other embodiments, the set screw 256 rests over atop of the head of the bone screws to prevent back-out of the bonescrews. In some embodiments, the set screw 256 comes pre-fixed with theplate 250. As shown in FIG. 9C, a single set screw 256 can be used toconveniently block a pair of bone screws. In other embodiments, eachbone screw can be assigned its own set screw, which can operateindependently of one another, to prevent back-out of the bone screw.

FIGS. 10A-10D illustrate different views of the low profile plate shownin FIGS. 9A-9D. From these views, one can see the lateral extensions 270that extend from the body of the plate 250. From these views, one canalso see the windows 272 (FIG. 10A) that extend along a substantiallength of the lateral extensions 270. In some embodiments, each window272 has a length greater than half the length of each lateral extension270, thereby advantageously increasing the radiolucency of the platingsystem. In some embodiments, the plate 250 is assembled axially to thespacer 210.

In some embodiments, the low profile plate 250 can also include indentedgripping sections 273 (shown in FIGS. 10A and 10B). These indentedgripping sections 273 advantageously provide a gripping surface for aninsertion instrument, thereby facilitating easy delivery of the plate toa spacer body during surgery.

FIGS. 11A-11D illustrate different views of a fourth alternativeembodiment of a low profile plate attached to a spacer according to someembodiments. Like the previous embodiment, the plating system 305includes a plate 350 having lateral arms or extensions 370 that extendaround an exterior surface of a spacer 310. The lateral extensions 370extend wider than the lateral extensions 70 in the first embodiment, anddo not necessarily have to interlock with the spacer 310. While in someembodiments, the plate 350 can be attached to the spacer 310 afterinserting the spacer 310 into a desired location in the body, in otherembodiments, the plate 350 can be pre-assembled with the spacer 310prior to inserting the plating system 305 into the desired location.

Like the spacer 10 in FIG. 1A, the spacer 310 is configured to have anupper surface 312, a lower surface 314, and a leading end 322. In someembodiments, the upper surface 312 and/or lower surface 314 includestexturing 316, such as teeth, ribs, ripples, etc. to assist in providingfrictional contact with adjacent vertebral bodies. In some embodiments,the leading end 322 of the spacer 310 can be slightly tapered, as shownin FIG. 11D. With the taper, the leading end 322 can serve as adistraction surface that helps the spacer 310 to be inserted into anintervertebral space. As shown in FIG. 11B, the leading end 322 can beslightly concave, though in other embodiments, the leading end 322 canbe straight or convex. In some embodiments, the spacer 310 can have agraft hole 320 that is completely enclosed. As shown in FIG. 11B, thegraft hole 320 can surrounded by four walls. In addition, the spacer 320can be comprised of four outer walls: two straight, one concave and oneconvex.

In some embodiments, the graft opening 320 (shown in FIG. 11B) of thespacer 310 is enclosed. While the graft opening 320 is rectangular withrounded edges, in other embodiments, the graft opening 320 can have adifferent shape. For example, in some embodiments, the graft opening 320can have curved walls, instead of straight walls, or can have taperedwalls, instead of straight walls.

Like spacer 10, the spacer 310 can be formed of a variety of materials.In some embodiments, the spacer 210 comprises allograft bone, while inother embodiments, the spacer 310 comprises PEEK.

The plate 350 is configured to have a pair of lateral extensions 370that receive the spacer 320. As shown in FIG. 11A, in some embodiments,the lateral extensions 370 include one or more windows 372 for improvingradiolucency of the plating system. In some embodiments, the plate 350is assembled axially to the spacer 310.

In addition to capturing the spacer 310, the plate 350 is alsoconfigured to attach into one or more vertebral bodies via one or morebone screws 88, 89. As shown in FIG. 9A, the plate 350 includes a firstscrew hole 351, a second screw hole 352 and a third screw hole 354 forreceiving bone screws 87, 88, 89 therein. In some embodiments, screwholes 352 and 354 are angled upwardly such that inserted bone screws 87,88 pass upward into an upper vertebral body, while screw hole 351 isangled downwardly such that inserted bone screw 89 passes downward intoa lower vertebral body. While the illustrated embodiment illustratesthree screw holes for receiving three bone screws, it is possible tohave one, two, four, five or more screw holes for receiving a differentnumber of bone screws.

Over time, it is possible for bone screws to back-out. The plate 350thus has blocking or set screws 356, 357, 358 (shown in FIG. 12C), eachof which corresponds to one of screw holes 351, 352, 354. As shown inFIG. 12C, the set screws 356, 357, 358 can be in an initial positionthat allows first, second and third bone screws to pass through holes351, 352, 354. Once the bone screws have been inserted through the holes351, 352, 354, the set screws 356, 357, 358 can be rotated (e.g., 90degrees), to thereby block the bone screws and prevent back out of thebone screws. In some embodiments, the set screws 356, 357, 358 abut aside of the head of the bone screws to prevent back-out of the bonescrews, while in other embodiments, the set screws 356, 357, 358 restover a top of the head of the bone screws to prevent back-out of thebone screws. In some embodiments, the set screws 356, 357, 358 comepre-fixed with the plate 350. As shown in FIG. 12C, a single set screw356, 357, 358 can be used to conveniently block a single bone screws. Inother embodiments, each set screw can be designed to block more than oneset screw to prevent back-out of the bone screw.

FIGS. 12A-12D illustrate different views of the low profile plate shownin FIGS. 11A-11D. From these views, one can see the lateral extensions370 that extend from the body of the plate 350. From these views, onecan also see the windows 372 (FIG. 12A) that extend along a substantiallength of the lateral extensions 370. In some embodiments, each window372 has a length greater than half the length of each lateral extension370, thereby advantageously increasing the radiolucency of the platingsystem. In some embodiments, the plate 350 is assembled axially to thespacer 310.

The plating systems describe include a plate that is independent from aspacer. The plate is low-profile and can be used with any type ofspacer, such as allograft or PEEK.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the scope or spirit of the invention. Moreover,the improved bone screw assemblies and related methods of use need notfeature all of the objects, advantages, features and aspects discussedabove. Thus, for example, those skilled in the art will recognize thatthe invention can be embodied or carried out in a manner that achievesor optimizes one advantage or a group of advantages as taught hereinwithout necessarily achieving other objects or advantages as may betaught or suggested herein. In addition, while a number of variations ofthe invention have been shown and described in detail, othermodifications and methods of use, which are within the scope of thisinvention, will be readily apparent to those of skill in the art basedupon this disclosure. It is contemplated that various combinations orsubcombinations of these specific features and aspects of embodimentsmay be made and still fall within the scope of the invention.Accordingly, it should be understood that various features and aspectsof the disclosed embodiments can be combined with or substituted for oneanother in order to form varying modes of the discussed bone screwassemblies. Thus, it is intended that the present invention cover themodifications and variations of this invention provided that they comewithin the scope of the appended claims or their equivalents.

What is claimed is:
 1. A spinal system comprising: a spacer forinserting into an intervertebral space, the spacer including: an uppersurface, a lower surface, and an opening that extends between the uppersurface to the lower surface; a plate for abutting the spacer, the plateincluding: a plate body, a first opening formed in the plate body forreceiving a first bone fastener, wherein the first opening is angled inan upward direction; a second opening formed in the plate body forreceiving a second bone fastener, wherein the second opening is angledin a downward direction; a blocking mechanism for preventing back-out ofboth the first and the second bone fasteners, wherein the blockingmechanism has a first position whereby the first and second bonefasteners can be inserted past the blocking mechanism and into the firstand second openings and a second position following rotation of theblocking mechanism whereby the first and second bone fasteners areprevented from backing out by the blocking mechanism, and a pair ofextensions that extend from the plate body, wherein the extensions areconfigured to engage the spacer, wherein each extension includes anenclosed window that extends along a length of the extension and whereineach of the windows receives a portion that extends laterally outwardfrom outer sidewalls of the spacer.
 2. The system of claim 1, whereinthe spacer is a C-shaped spacer.
 3. The system of claim 1, wherein thespacer comprises an upper chamfer and a lower chamfer.
 4. The system ofclaim 1, wherein the pair of extensions that extend from the plate bodyextend around an outer surface of the spacer.
 5. The system of claim 4,wherein the pair of extensions include inward protrusions for insertinginto outer sidewalls of the spacer.
 6. The system of claim 5, whereinthe spacer includes a pair of notches that correspond to the pair ofextension of the plate to form a first locking mechanism between theplate and the spacer.
 7. The system of claim 1, wherein the opening inthe spacer is bounded by at least one convex surface.
 8. A spinal systemcomprising: a spacer for inserting into an intervertebral space, thespacer including: an upper surface, a lower surface, and an opening thatextends between the upper surface to the lower surface, wherein thespacer further includes a concave leading end; a plate for abutting thespacer, the plate including: a plate body, a first opening formed in theplate body for receiving a first bone screw, wherein the first openingis angled in an upward direction; a second opening formed in the platebody for receiving a second bone screw, wherein the second opening isangled in a downward direction; a pair of extensions that extend fromthe plate body, wherein each extension includes an enclosed window thatextends along a length of the extension and wherein each of the windowsreceives a portion that extends laterally outward from outer sidewallsof the spacer.
 9. The system of claim 8, wherein the portion thatextends laterally outward from the outer sidewalls is a hump portion.10. The system of claim 8, wherein the pair of extensions of the platecomprise inward protrusions that extend into notches formed on an outersurface of the spacer.
 11. The system of claim 8, wherein the plateincludes a set screw, and the set screw is configured to preventback-out of both the first and the second bone screws in the plate. 12.The system of claim 11, further comprising the first and second bonescrews, wherein upon rotation of the set screw, the set screw abuts sidesurfaces of heads of the first and second bone screws.
 13. The system ofclaim 8, wherein the leading end of the spacer is tapered.
 14. Thesystem of claim 8, wherein the spacer is substantially C-shaped andincludes two side arms.
 15. A spinal system comprising: a spacer forinserting into an intervertebral space, the spacer including: an uppersurface, a lower surface, and an opening that extends from the uppersurface to the lower surface; a plate for abutting the spacer, whereinthe spacer is substantially C-shaped and includes two side arms, theplate including: a plate body, a first opening formed in the plate bodyfor receiving a first bone screw, wherein the first opening is angled inan upward direction; a second opening formed in the plate body forreceiving a second bone screw, wherein the second opening is angled in adownward direction; and a pair of extensions that extend from the platebody, wherein the extensions are configured to engage the spacer, andwherein each extension includes an enclosed window that extends along alength of the extensions; and wherein each of the enclosed windowsreceives a portion that extends laterally outward from outer surfaces ofthe arms of the spacer, respectively, to join the plate and spacertogether.
 16. The system of claim 15, wherein the spacer comprises anallograft spacer.
 17. The system of claim of claim 16, wherein theallograft spacer includes at least one chamfer for accommodating eitherthe first bone screw or the second bone screw.
 18. The system of claim17, wherein the spacer comprises a PEEK spacer.
 19. The system of claim15, wherein each window receives a hump portion of the spacer to createa locking mechanism between the plate and the spacer.
 20. The system ofclaim 15, wherein each of the arms of the spacer includes a notch forreceiving a corresponding protrusion from the extensions of the plate.